A simple bound on blocking probability for pilot channel in WCDMA systems

Abstract

There are many wireless systems such as global system for mobile communication (GSM), IS-95, and wideband code division multiple access (WCDMA) etc. Among them, WCDMA which is 3rd generation wireless system is operating and will be served all over the world in 2 years. Contrary to 2nd generation systems such as GSM and IS-95, WCDMA systems provide more enhanced service and better quality. But WCDMA systems are only recently deployed, we need many performance evaluations for WCDMA systems. The blocking probability for pilot channel of WCDMA is one of main performance evaluations for WCDMA systems. A blocking probability for pilot channel of WCDMA is the probability that a mobile station can not receive pilot signals from base stations. When a mobile station doesn``t receive pilot signals, WCDMA service will not be available for the mobile station. Also, blocking probability is the most important measurement for handover algorithm in WCDMA systems. Blocking probability is influenced by received pilot signals and all interference signals. Wireless channels exhibit path-loss, shadowing and fast fading. Fast fading is neglected since, having a short correlation relative to that of shadowing (ranging around 10``s of meters), gets averaged out at the time scales tinder consideration. Between pathloss and shadowing, received interference signals have slim of lognormal distributions because of shadowing. But it is hard to compute blocking probability because there``s no exact expectation value for sum of lognormal random variables. Therefore, using bound of blocking probability is more efficient and easy to evaluate wireless systems. In this thesis, we present a simple bound using Jansen``s arithmetic geometric mean inequality to obtain blocking probability for a WCDMA pilot channel. When a threshold value of blocking probability and standard deviation of each lognormal random variable are low the proposed bound is well suited for simulation results. In addition, re...